// ==UserScript==
// @name         ChatGPT DeBloat
// @namespace    gpt.debloat
// @version      1.1.0
// @description  Keep last N messages visible; unload media in hidden ones; Show Older/All works without breaking the page.
// @match        https://chat.openai.com/*
// @match        https://chatgpt.com/*
// @run-at       document-idle
// @grant        none
// ==/UserScript==

(() => {
  'use strict';

  // ---------- Config (saved across sessions) ----------
  const CFG = {
    keepLast: loadNum('cgpt_keep_last_safe2', 120),
    chunk:    loadNum('cgpt_chunk_safe2', 40),
    auto:     loadBool('cgpt_auto_safe2', true),
    unloadHiddenMedia: loadBool('cgpt_unload_media2', true),
  };

  // ---------- Utilities ----------
  function save(k,v){ try{ localStorage.setItem(k, JSON.stringify(v)); }catch{} }
  function loadNum(k,d){ try{ const v = JSON.parse(localStorage.getItem(k)); return Number.isFinite(v)?v:d; }catch{ return d; } }
  function loadBool(k,d){ try{ const v = JSON.parse(localStorage.getItem(k)); return typeof v==='boolean'?v:d; }catch{ return d; } }

  const BLANK_IMG = 'data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///ywAAAAAAQABAAACAUwAOw==';

  function getContainer(){
    return document.querySelector('[data-testid="conversation-turns"]') ||
           document.querySelector('main') || document.body;
  }

  // NOTE: include hidden nodes (no offsetParent filtering!)
  function getMessageNodes(){
    const root = getContainer();
    if (!root) return [];
    const list = root.querySelectorAll('[data-testid^="conversation-turn-"], div[data-message-id], article');
    // de-dup while preserving order
    const seen = new Set();
    const out = [];
    list.forEach(n => { if (!seen.has(n)) { seen.add(n); out.push(n); } });
    return out;
  }

  function unloadMediaIn(node){
    if(!CFG.unloadHiddenMedia) return;
    node.querySelectorAll('img').forEach(img=>{
      if(img.dataset._cgptUnloaded) return;
      if(img.src && img.src !== BLANK_IMG){ img.dataset._cgptSrc = img.src; img.src = BLANK_IMG; }
      if(img.srcset){ img.dataset._cgptSrcset = img.srcset; img.srcset = ''; }
      img.loading = 'lazy'; img.decoding='async';
      img.dataset._cgptUnloaded = '1';
    });
    node.querySelectorAll('video').forEach(v=>{
      if(v.dataset._cgptUnloaded) return;
      try{ v.pause(); }catch{}
      const s = v.getAttribute('src');
      if(s){ v.dataset._cgptSrc = s; v.removeAttribute('src'); }
      v.querySelectorAll('source').forEach(src=>{
        const s2 = src.getAttribute('src');
        if(s2){ src.dataset._cgptSrc = s2; src.removeAttribute('src'); }
      });
      v.load?.();
      v.dataset._cgptUnloaded = '1';
    });
  }

  function restoreMediaIn(node){
    node.querySelectorAll('img').forEach(img=>{
      if(img.dataset._cgptSrc){ img.src = img.dataset._cgptSrc; delete img.dataset._cgptSrc; }
      if(img.dataset._cgptSrcset){ img.srcset = img.dataset._cgptSrcset; delete img.dataset._cgptSrcset; }
      if(img.dataset._cgptUnloaded){ delete img.dataset._cgptUnloaded; }
    });
    node.querySelectorAll('video').forEach(v=>{
      if(v.dataset._cgptSrc){ v.setAttribute('src', v.dataset._cgptSrc); delete v.dataset._cgptSrc; }
      v.querySelectorAll('source').forEach(src=>{
        if(src.dataset._cgptSrc){ src.setAttribute('src', src.dataset._cgptSrc); delete src.dataset._cgptSrc; }
      });
      if(v.dataset._cgptUnloaded){ delete v.dataset._cgptUnloaded; }
      try{ v.load?.(); }catch{}
    });
  }

  // ---------- Trim & Restore ----------
  function applyTrim(){
    const nodes = getMessageNodes();
    const total = nodes.length;
    const toKeep = Math.min(CFG.keepLast, total);
    const cut = total - toKeep;

    for(let i=0;i<total;i++){
      const n = nodes[i];
      if(i < cut){
        if(!n.classList.contains('cgpt-safe-hidden')){
          if(CFG.unloadHiddenMedia) unloadMediaIn(n);
          n.classList.add('cgpt-safe-hidden');
        }
      } else {
        if(n.classList.contains('cgpt-safe-hidden')){
          n.classList.remove('cgpt-safe-hidden');
          restoreMediaIn(n);
        }
      }
    }
    updateStats(total, Math.max(0, cut));
  }

  function showOlderChunk(){
    CFG.keepLast = Math.max(20, CFG.keepLast + CFG.chunk);
    save('cgpt_keep_last_safe2', CFG.keepLast);
    applyTrim();
    refreshUI();
  }

  function showAll(){
    CFG.keepLast = Number.MAX_SAFE_INTEGER;
    save('cgpt_keep_last_safe2', CFG.keepLast);
    applyTrim();
    refreshUI();
  }

  function resetAll(){
    // show everything and disable auto
    CFG.keepLast = Number.MAX_SAFE_INTEGER;
    CFG.auto = false;
    save('cgpt_keep_last_safe2', CFG.keepLast);
    save('cgpt_auto_safe2', CFG.auto);
    const nodes = getMessageNodes();
    nodes.forEach(n=>{
      n.classList.remove('cgpt-safe-hidden');
      restoreMediaIn(n);
    });
    updateStats(nodes.length, 0);
    refreshUI();
  }

  // ---------- UI ----------
  const STYLE = `
    .cgpt-safe-hidden{display:none!important}
    #cgpt-ui{position:fixed;right:14px;bottom:14px;z-index:2147483647;background:rgba(22,22,28,.95);
      color:#eee;border:1px solid #3b3b48;border-radius:12px;padding:10px 12px;
      font:12px/1.4 ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto;box-shadow:0 8px 24px rgba(0,0,0,.35);backdrop-filter:blur(4px);user-select:none}
    #cgpt-ui .row{display:flex;gap:8px;align-items:center;margin:6px 0;flex-wrap:wrap}
    #cgpt-ui button,#cgpt-ui input{background:#15151b;color:#eee;border:1px solid #40404f;border-radius:8px;padding:6px 8px}
    #cgpt-ui .muted{color:#b7b7c7}
    #cgpt-ui .drag{cursor:move}
  `;
  function ensureStyle(){
    if(document.getElementById('cgpt-style')) return;
    const s=document.createElement('style'); s.id='cgpt-style'; s.textContent=STYLE; document.head.appendChild(s);
  }

  function buildUI(){
    if(document.getElementById('cgpt-ui')) return;
    const box=document.createElement('div'); box.id='cgpt-ui';
    box.innerHTML = `
      <div class="row drag"><strong>GPT DeBloat</strong><span id="cgpt-stats" class="muted"></span></div>
      <div class="row">
        Keep last <input id="cgpt-keep" type="number" min="20" max="3000" step="10" style="width:80px">
        <button id="cgpt-trim">Trim</button>
        <button id="cgpt-more">Show older +${CFG.chunk}</button>
      </div>
      <div class="row">
        <label><input id="cgpt-auto" type="checkbox"> Auto</label>
        <label><input id="cgpt-unload" type="checkbox"> Unload media</label>
        <button id="cgpt-all">Show all</button>
        <button id="cgpt-reset">Reset</button>
        <button id="cgpt-close" title="Hide">✕</button>
      </div>
    `;
    document.body.appendChild(box);

    // wire
    const keep = document.getElementById('cgpt-keep');
    keep.value = CFG.keepLast === Number.MAX_SAFE_INTEGER ? 3000 : CFG.keepLast;
    document.getElementById('cgpt-auto').checked = CFG.auto;
    document.getElementById('cgpt-unload').checked = CFG.unloadHiddenMedia;

    document.getElementById('cgpt-trim').onclick = applyTrim;
    document.getElementById('cgpt-more').onclick = showOlderChunk;
    document.getElementById('cgpt-all').onclick = showAll;
    document.getElementById('cgpt-reset').onclick = resetAll;
    document.getElementById('cgpt-close').onclick = ()=>{ box.style.display='none'; };

    keep.onchange = e=>{
      const v = Math.max(20, Math.min(3000, Number(e.target.value)||120));
      CFG.keepLast = v; save('cgpt_keep_last_safe2', v); applyTrim();
    };
    document.getElementById('cgpt-auto').onchange = e=>{
      CFG.auto = !!e.target.checked; save('cgpt_auto_safe2', CFG.auto);
      CFG.auto ? startObserver() : stopObserver();
    };
    document.getElementById('cgpt-unload').onchange = e=>{
      CFG.unloadHiddenMedia = !!e.target.checked; save('cgpt_unload_media2', CFG.unloadHiddenMedia);
      applyTrim();
    };

    makeDraggable(box);
  }

  function updateStats(total, hidden){
    const el=document.getElementById('cgpt-stats');
    if(el) el.textContent = ` · ${total-hidden}/${total} showing`;
  }

  function refreshUI(){
    const keepEl=document.getElementById('cgpt-keep');
    if(keepEl) keepEl.value = (CFG.keepLast===Number.MAX_SAFE_INTEGER)?3000:CFG.keepLast;
    const autoEl=document.getElementById('cgpt-auto'); if(autoEl) autoEl.checked = CFG.auto;
    const unEl=document.getElementById('cgpt-unload'); if(unEl) unEl.checked = CFG.unloadHiddenMedia;
  }

  function makeDraggable(el){
    let sx=0, sy=0, ox=0, oy=0, drag=false;
    const h = el.querySelector('.drag') || el;
    h.addEventListener('mousedown', e=>{
      if(e.button!==0) return;
      drag=true; sx=e.clientX; sy=e.clientY;
      const r=el.getBoundingClientRect(); ox=r.left; oy=r.top; e.preventDefault();
    });
    window.addEventListener('mousemove', e=>{
      if(!drag) return;
      const nx = Math.max(6, ox + (e.clientX - sx));
      const ny = Math.max(6, oy + (e.clientY - sy));
      el.style.right='auto'; el.style.bottom='auto';
      el.style.left = nx+'px'; el.style.top = ny+'px';
    });
    window.addEventListener('mouseup', ()=>drag=false);
  }

  // ---------- Observer ----------
  let MO=null, deb=null;
  function startObserver(){
    const root=getContainer(); if(!root) return;
    stopObserver();
    MO = new MutationObserver(()=>{
      if(!CFG.auto) return;
      clearTimeout(deb); deb = setTimeout(applyTrim, 200);
    });
    MO.observe(root, { childList:true, subtree:true });
  }
  function stopObserver(){ try{ MO?.disconnect(); }catch{} }

  // ---------- Boot ----------
  function boot(){
    ensureStyle();
    buildUI();
    setTimeout(applyTrim, 600);
    if(CFG.auto) startObserver();

    // handle SPA route changes
    let prev = location.href;
    setInterval(()=>{ if(location.href!==prev){ prev=location.href; setTimeout(()=>{ applyTrim(); if(CFG.auto){ startObserver(); } }, 600);} }, 500);
  }

  if(document.readyState==='complete' || document.readyState==='interactive') boot();
  else document.addEventListener('DOMContentLoaded', boot, { once:true });
})();